Mineral oil and method of its manufacture



Patented Dec. 3, 1935 UNITED STATES PATENT OFFICE MINERAL OIL AND METHOD @F ITS MANUFACTURE No Drawing. Application August 19, 1933, Serial No. 685,855. In the Netherlands August 22,

15 Claims.

This invention relates to methods of lowering pour points of oils containing in solution or in colloidal suspension normally solid substances of the type of paraflin wax, and to methods of producing concentrated mixtures of highly active pour point-reducing substances.

Some hydrocarbon oils, as, for instance, those originating from paraflin base crude petroleum and those obtained by hydrogenation, may show a large increase of viscosity upon their temperatures being lowered. Their viscosity may even be increased to the extent of rendering the oil entirely unpourable. This so-called congelation of mineral. oils is ascribed to the crystallizable paraffin wax present therein. At a low temperature this paraffin wax forms a needle-like structure in the oil, with the result that the latter loses in fluidity.

It is evident that lubricants having this property cannot be used in engines operating at low temperatures.

Various methods have already been proposed to separate'the crystallizable parafifin wax from the oil.

V It has also been proposed to prevent the oil from becoming viscous by adding specie. cubstance-s.

Hwrvever, not ail hydrocarbon oils consisting of or originating from parafiin base materials have the property of becoming excessively viscous on being cooled. This property of certain paraffin base oils of having relatively low pour points appeared to be due to the fact that such oils naturally contain substances which tend to preclude the undesirable crystallization of the paraiiin wax. The presence of such substances in the same oils could be demonstrated by separating such substances from a portion of such an oil by one of the methods herein described and then adding the separated substances, or their concentrates, to the other portion of the original oil, whereby a lowering of the original pour point of the oil is effected. The pour point of the dewaxed portion of the oil is, of course, lower than the original pour point. It was also found that when the said substances were concentrated by using, for example, bleaching or diatomaceous earth and the like, on which they appeared to be adsorbed, then separated from the adsorbing medium, and admixed in small quantities to an easily congealing mineral oil, such as the original oil, or some other oil, or a mixture containing a mineral oil, the pour point of such oil was appreciably reduced. Moreover, it was found that the substances having the above mentioned pour point reducing action can be obtained not only from natural or synthetic mineral oils or fractions thereof, but are also present in and can be recovered from other materials, such as, e. g., wool fat.

Among synthetic oils which yield concentrated 5 pour point reducing agents, may be mentioned condensation products of cyclic hydrocarbons, or their hydroxy and other substituted derivatives, or heterogenous ring compounds with N or O in the ring, with parafiinic hydrocarbons or various other open chain compounds such as higher fatty acids, aliphatic alcohols, etc. These products represent complex mixtures consisting substan-- tially of compounds whose molecules are built of more or less complex cyclic nuclei with rela- 15 tively long side chains attached thereto, and some of which compounds appear to be more active in lowering pour points of mineral oils than the the others. As an example of one form of substances of this type, which may be used as a 20 source of the active pour point reducers of this invention, may be mentioned the substances described in the U. S. Patent No. 1,815,022.

According to the present invention, the active pour point-reducing substances may be obtained 25 from the materials containing them by extraction with suitable adsorbing agents, such as various adsorbing clays, e, g. bauxite, or charcoal, or silica gel, and other similar finely divided materials or their mixtures; it has also been discovered 30 out under a suitable pressure or vacuum, or with 45 steam, if desired.

Example 1 "400 gr. of a Java oil residue was dissolved in 3 litres of butanone. The solution was then cooled, causing the paraffin wax to crystalize out. The paraflin wax was filtered off and freed from the solvent by heating; it was then dissolved in 4 litres of benzine, and the solution, after removal of the insoluble substances (asphaltenes), was decolorized with gr. of terrana. The spent terrana, after being washed with benzine, was extracted with pyridine, from which an active substance was obtained by distilling off the solvent, which, when added to a Roumanian parafiin base lubricating oil in a quantity of 0.25%, reduced the pour point of this oil by 15 0.

Example 2 A mixture of 1 kg. of commercial parafiin wax and 50 gms. of the synthetic material, prepared substantially according to the specification of the U. S. Patent No. 1,815,022, was dissolved in 7 kgs. of a butanone-benzine mixture (2:1). The resulting solution was cooled, and the precipitated waxy material was filtered off and then redissolved in benzine. This solution was decolorized with terrana and separated therefrom. The spent terrana was repeatedly washed with benzine in order to remove the excess wax and then extracted with pyridine. This solvent was removed from the extract by distillation and the remaining residue, consisting of highly active pour point reducing substances, weighed 2.3 gms. When added in the proportion of .08% to a Roumanian paraffinic lubricating oil this residue caused lowering of its pour point by 15 C. The equally efiective quantity of the original synthetic material, mentioned above, was .45%, thus indicating that the new product was about 5 times more efiective than the said synthetic material.

It is to be noted, that while the above examples disclosed certain specific solvents, like butanone, benzine, and pyridine, which were used in various stages of the processes, as well as the particular oil residue (Java oil residue) and the synthetic material prepared in accordance with the mentioned patent,these and other details set forth in the examples are to be considered merely as illustrative forms of practising the invention, which, however, may be varied in their particulars. For instance, hydrocarbon oils consisting of substances having relatively high molecular weights and obtained either by distillation, or by cracking, or by hydrogenation, or by extraction of natural mineral or vegetable oils, or animal oils or fats, may be used as sources 01 the active pour point-reducing substances. Such oils may have originally either relatively high pour points, when the concentration oi. the easily congealing parafiin wax-like substances is relatively great, or their pour points may be rela tively low when the concentration of the active substances is sufiiciently high to be effective in preventing solidification of theeils, which may be caused by congealing of certain waxy substances upon cooling. It was also found that some of the oils contain highly effective pour point-reducing substances even in the absence of the paraflin wax-like materials; these pour point-reducing substances can be separated from such oils by the methods described in this specification. In general, the materials, naturally occurring or synthetic, which are found to contain the active pour point reducers, are composed of substances of relatively high molecular weights and whose boiling temperatures at atmospheric pressure are beyond the temperatures at which they decompose, but may be distilled, when desired, either under vacuum or in the presence of steam or other inert vapour or gas.

The extraction of active substances by means of a suitable adsorbing agent or agents may be carried out either directly from the above mentioned materials or from their solutions or colloidal suspensions in one of the common organic solvents, exemplified by benzine, benzol, and various other aliphatic or aromatic hydrocarbons, their mixtures, etc. It was found that some classes of solvents, such as for instance ketones, cannot be employed, as in the presence of these solvents the adsorption of the active substances by the adsorbing agents does not take place or only partially. The adsorbing agent is then separated from the treated material and, if desired, after washing with one of the above-mentioned solvents, is again washed with a solvent for the desired active substances; although other organic solvents may be used for this last washing step, it is preferable to extract these substances with a solvent of the following types: pyridine, xylene, carbon tetrachloride, carbon disulphide, low boiling Edeleanu extracts from mineral oils, or mixtures of two or more of these solvents. In case of using parafiin wax as an adsorbing agent, the separated wax with adsorbed active substances may be redissolved in one of the common organic solvents mentioned above and then treated with clay. It is also possible to melt the separated wax and to treat it in molten condition with finely divided adsorbing agents such as clay, the use of of solvent for the wax in this case being superfluous. The more or less spent clay separated together with adsorbed pour point-reducing substances is then extracted with a solvent for said substances, as described. These substances may also be extracted directly from the dissolved wax with a preferential solvent; in either case they are recovered from the solvent usually by distillation.

It should further be noted that this invention is not bound to any theory explaining the complex composition or molecular structure or mechanism of action of the pour point-reducing substances obtained by the disclosed methods, but is directed to the substances of unknown, as yet, composition, which are obtainable by one of these methods.

I claim as my invention:

1. In the process of obtaining a solution of concentrated pour point-reducing substances from a mixture containing the same, the steps comprising separating said substances from said mixture by treating the mixture with an adsorbing agent, separating said agent together with the adsorbed substances from the rest of the mixture and finally extracting the adsorbed substances from the separated adsorbing agent by means of a solvent in which the said pour, point reducing substances readily dissolve.

2. The process of claim 1 wherein the mixture containing pour point-reducing substances is selected from the group consisting of: a paraffin base mineral oil containing paramn wax and having a relatively low pour point, and a parafiin wax containing said substances.

3. The process of claim 1 wherein the mixture containing pour point-reducing substances is wool fat.

4. The process of claim 1 wherein the adsorbing agent is paraifin wax.

5. The process of claim 1 wherein the adsorbing agent is selected from the group consisting of: diatomaceous earth, bleaching earth, bauxite, charcoal, and silica gel.

6. The process of claim 1 wherein the final separation of the pour point-reducing substances from an adsorbing agent is efiected by extraction with a solvent for said substances selected from the group consisting of pyridine, xylene, carbon tetrachloride, carbon disulphide, low boiling nonparaffinic extracts from mineral oils.

7. In the process of obtaining a solution of concentrated pour point-reducing substances from a mixture containing such substances together with parafiln wax, the steps comprising cooling the mixture below the melting point of the wax, thereby causing the wax to solidify and the pour point-reducing substances to be adsorbed on the solidified wax, separating the wax with the adsorbed substances from the rest of the mixture, liquefying the wax by heating, treating the molten mixture of wax and adsorbed substances with a finely divided adsorbing agent to separate said adsorbed substances from the molten wax, separating the finely divided substances together with the adsorbed substances from the wax and extracting the adsorbed substances from the finely divided adsorbing agent by means of a solvent in which the said pour point-reducing substances readily dissolve.

8. In the process of obtaining a solution of concentrated pour point-reducing substances, from a mixture containing such substances, the steps comprising adding paraffin wax to said mixture, cooling the mixture below the melting point of the wax, thereby causing the wax to solidify and the pour point-reducing substances to be adsorbed on the solidified wax, separating the wax with the adsorbed substances from the rest of the mixture, liquefying the wax by heating, treating the molten mixture of wax and adsorbed substances with a finely divided adsorbing agent to separate said adsorbed substances from the molten wax, separating the finely divided substances together with the adsorbed substances from the wax and extracting the adsorbed substances from the finely divided adsorbing agent by means of a solvent in which the said pour point reducing substances readily dissolve.

9. In the process of obtaining concentrated pour point-reducing substances from a mixture containing the same, the steps comprising dissolving a quantity of parafiin wax in said mixture, then cooling the mixture, below the melting temperature of the ,wax, thereby causing separation of the wax together with the adsorbed pour pointreducing substances from the rest of the mixture, dissolving the separated wax in a solvent, thereby forming a solution of the substances which were adsorbed on the wax, treating said solution with a finely divided adsorbing agent to separate said dissolved substances from the dissolved wax and the solvent, and then extracting the adsorbed substances from the separated finely divided adsorbing agent by means of a solvent in which the said pour point reducing substances readily dissolve.

10. The process of obtaining a solution of concentrated pour point-reducing substances from a mixture containing such substances together with parafiin wax, the steps comprising cooling the mixture below melting temperature of the wax, thereby causing the wax to solidify and the pour point-reducing substances to be adsorbed on the solidified wax, separating the wax with the adsorbed substances from the rest of the mixture, dissolving the separated wax in a solvent, thereby forming a solution of the substances which were adsorbed on the wax, treating said solution 5 with a finely divided adsorbing agent to separate said dissolved substances from the dissolved wax and the solvent, and then extracting the adsorbed substances from the separated finely divided adsorbing agent by means of a solvent in which the said pour point reducing substances readily dissolve.

11. In the process of obtaining a solution of concentrated pour point-reducing substances from a mixture containing the same, the steps comprising separating said substances from said mixture by treating the mixture with an adsorbing agent, separating said agent together with the adsorbed substances from the rest of the mixture, extracting the adsorbed substances from 20 the separated adsorbing agent by means of a solvent for the pour point-reducing substances and then separating the solvent from the extracted substances.

12. A composition comprising a mineral oil 25 containing waxy components and, added thereto, an efiective quantity of a complex mixture of pour point-reducing substances obtained by an adsorption treatment of a mixture containing such substances with an adsorbing agent, wherefrom said mixture was consequently extracted with a solvent and, then, separated from the solvent.

13. A composite oil having a relatively low pour point comprising a mineral oil containingwaxy components and having, therefore, a relatively high pour point and an effective quantity of a complex mixture of pour point-reducing substances obtained by an adsorption treatment of a natural mineral oil containing such substances with an adsorbing agent, wherefrom said mixture was consequently extracted with a solvent and, then, separated from the solvent.

14. A composite oil having a relatively low pour point comprising a mineral oil containing waxy components and having, therefore, a relatively 45 high pour point and an effective quantity of a complex mixture of pour point-reducing substances obtained by an adsorption treatment of a synthetic oil containing such substances with an adsorbing agent, wherefrom said mixture was 50 consequently extracted with a solvent and, then, separated from the solvent.

15. In the process of obtaining a solution 01 concentrated pour point-reducing substances from a mixture containing the same, the steps comprising separating said substances from said mix-' ture by treating the mixture with an adsorbing agent, separating said agent together with the adsorbed substances from the rest of the mixture, washing the separated agent with a solvent for other adsorbed material than the pour point reducing substances, and finally extracting the adsorbed substances from the separated adsorbing agent by means of a solvent in which the said pour point reducing substances readily dissolve.

HIJMAN LIMBUR 

